1. Field of the Invention
The present invention relates to a coordinate measuring machine with a drive and braking arrangement for a spindle sleeve which is displaceable in the Z-direction through the intermediary of a threaded spindle.
2. Discussion of the Prior Art
From the disclosure of German Laid-Open Patent Appln. No. 35 14 961, there has become known a drive arrangement on a coordinate measuring machine, which serves for the movement of a spindle sleeve in the Z-direction through the utilization of a threaded spindle. This published patent specification relates to the aspect that a radial impact against the threaded spindle is not transmitted to the spindle sleeve, and additionally it is possible to encounter a movement about a wobble or tumbling axis. However, there is no discussion in this publication with respect to the drive and the braking of the threaded spindle for effectuating the movement of the spindle sleeve.
Heretofore, it has been known in the practice to employ an electric motor with a brake for the drive of the threaded spindle. In that instance, the driving force was transmitted from the motor shaft through a metal bellows coupling to a stub shaft, on which there were supported a permanent magnet brake and a wide drive pulley for two pulley belts. For this type of dual-belt drive, it was necessary to provide a dual belt supervision and dual belt tensioners.